The safety and efficacy of biological candidates are critical to their clinical success. The proteinaceous nature of many drug candidates can lead to an immunogenic response in the patient. The proteins may aggregate or have epitopes that are recognized by the immune system. Once the immune system is activated, the efficacy of the biotherapeutic declines as the system attempts to clear the antigen. The immune response itself affects product safety as cytokine release can be toxic to the patient. For biotherapeutic development, avoiding this response is vital for success.
Alternatively, for vaccine development, triggering an immune response is desired. Designing and assessing vaccine candidates for the appropriate immune response is critical for their success.
Animal testing is used in an effort to assess the potential immunogenicity of biotherapeutic and vaccine candidates. The response in animals can be helpful to researchers; however, it is often not a good indicator of what the human immune response will be to the biological candidate.